Comparison of the Antibacterial Effect of AH26, Adseal and Beta RCS Root Canal Sealers against Enterococcus Faecalis, an in Vitro Study.

Objectives: Antibacterial activity against endodontic pathogens is a desirable feature for root canal sealers. The objective of this study was to compare the antibacterial effect of three resin-based endodontic sealers (AH26, Adseal, and Beta RCS) against Enterococcus faecalis in vitro. Materials and Methods: The antibacterial properties of the sealers were assessed against E. faecalis using agar diffusion test (ADT) for fresh state (N=10) and direct contact test (DCT) for freshly-mixed and set states of the materials (N=10). In ADT, the diameter of the zones of inhibition was measured after 24h of contact. In DCT, the colony-forming units of the bacteria were counted after 30 minutes and 180 minutes of exposure. The results were analyzed with two-way ANOVA and independent sample t-test. P<0.05 was considered significant. Results: Regarding DCT results, all test materials indicated an antibacterial effect, both in freshly-mixed and set states. The highest antibacterial effect was related to Adseal, whereas the lowest was observed in Beta RCS. There was a significant difference between all study groups (different sealers, setting states, and contact times; P<0.001), except for freshly-mixed AH26 and Adseal at 180 minutes (P>0.05). According to ADT, AH26 and Adseal represented the widest and the smallest inhibition zones, respectively (P<0.001). Conclusion: Within the limitations of this in vitro study, AH26, Adseal, and Beta RCS showed antibacterial effects against E. faecalis in both freshly-mixed and set states. The antibacterial effect increased over time in all of the studied sealers.

Root canal dentin wear during final irrigation in endodontic retreatment with passive ultrasonic irrigation and easy clean instruments.

Context: Complementary procedures have been proposed to improve the endodontic retreatments. Aim: The aim of this study was to evaluate, by microcomputed tomography (micro-CT), the dentin wear caused by passive ultrasonic irrigation (PUI) and easy clean (EC) instruments, when used for the final removal of filling material during endodontic retreatment. Methods: Thirty-six mesial roots of the lower first molars were divided into four groups (n = 9), according to the final irrigation and sealer: PUI/AH Plus, EC/AH Plus, PUI/Total Fill (TF), and EC/TF. Canal volume was evaluated, both before and after the final irrigation, by micro-CT analysis. The Kruskal-Wallis test was used to compare the volumes among groups and the paired Wilcoxon test was used to compare the volume values before and after the final irrigation within each group. Results: Both complementary cleaning procedures promoted dentin wear that was observed only when the volume was analyzed for each third of the root canal. In the apical third, both instruments showed significant wear, where the use of the EC instrument resulted in greater wear than the PUI, in teeth filled with both AH Plus and TF BC Sealers (P < 0.05). Conclusion: Both complementary cleaning procedures promoted dentin wear and must be used cautiously.

Morphometric parameters of dental pulp in immature teeth in a sheep model after mechanical pulp exposure and restoration with reinforced zinc oxide-eugenol.

Background: The aim of the study was to investigate the morphometric parameters of dental pulp in open apices immature teeth in a sheep model after mechanical pulp exposure and restoration with reinforced zinc oxide-eugenol. Materials and Methods: In this experimental study, a total of 12 immature mandibular central incisors from six adult male sheep, weighing 30-40 kg and with the age of 1 year old with Merino race were examined. After anesthesia, the pulps of the teeth in the case group were mechanically exposed and then were restored with reinforced zinc oxide-eugenol and amalgam. In the control group, the teeth remained intact. The animals were sacrificed at intervals of 2, 4, 6, and 8 weeks (E2, E4, E6, and E8) in the case and 2 and 8 weeks (C2 and C8) in the control groups. Then, their teeth were removed with the surrounding supporting tissues and alveolar bones. Tissue processing and staining were done, and the sections were examined under a light microscope. The Kruskal-Wallis and Mann-Whitney U tests were used to analyze the data and compare the changes between the two groups. P < 0.05 was considered statistically significant. Results: In response to mechanical exposure, reparative or tertiary dentin was formed, and its thickness increased during the time of the study. The thickness of the odontoblastic layer in the E4 group was the highest amount. The pulp chamber diameter in the C2 group was significantly larger than the other groups, and the diameter of the apical foramen in the E8 was decreased significantly compared to the controls (P < 0.05). Conclusion: In response to mechanical exposure and restoration with reinforced zinc oxide-eugenol, some morphometric parameters of the dental pulp changed significantly in the sheep model compared to the controls.

Analysis of the cytotoxicity and bioactivity of CeraSeal, BioRoot™ and AH Plus® sealers in pre-osteoblast lineage cells.

BACKGROUND: The objective of the present study was to evaluate in vitro the cytotoxicity and bioactivity of various endodontic sealers (CeraSeal, BioRoot™ and AH Plus®) in pre-osteoblast mouse cells (MC3T3 cells). METHODS: MC3T3 cells (ATCC CRL-2594) were plated in 1 × 104 cells/well in 96-well plates in contact with endodontic sealers at concentrations of 1:10 and 1:100. Cell viability was evaluated by MTT assay after 24 and 48 h. In addition, sealer bioactivity was measured by RT-PCR for mediator of inflammation (Tnf, Ptgs2) and mineralization (Runx2, Msx1, Ssp1 and Dmp1) after 24 h and by Alizarin Red S Assay of mineralization after 28 days. Data were analyzed using one-way ANOVA followed by the Tukey's post-test at a significance level of 5%. RESULTS: BioRoot™ presented 24-hour cytotoxicity (p < 0.05) at 1:10 concentration. In the period of 48 h, no endodontic cement was cytotoxic to the cells compared to the control (p > 0.05). TNF-α gene expression was induced by AH Plus® (p < 0.05), while Ptgs2 was induced by the CeraSeal and BioRoot™ (p < 0.05). The expression of Runx2 was stimulated by BioRoot™ and AH Plus® (p < 0.05). In contrast, the expression of Dmp-1 Dmp1 was higher for the CeraSeal and BioRoot™ (p < 0.05). Nonetheless, the sealers did not impact the formation of mineralization nodules (p > 0.05). CONCLUSION: CeraSeal, BioRoot™ and AH Plus® sealers were not cytotoxic to MC3T3 cells within 48 h, but differentially induced the expression of genes related to inflammation and mineralization without impacting biomineralization by the cells.

[Sealing effect of GuttaFlow2 in curved root canals].

OBJECTIVE: To evaluate the sealing ability of GuttaFlow2 single cone obturation in curved root canals. METHODS: (1) Slight, moderate and severe curved 3D printed root canals were made. After instrumentation, these samples were randomly divided into 2 groups (n = 10) according to different root canal filling techniques: GuttaFlow2 single cone group (GF2) and AH-Plus warm vertical compation group (WVC). All the samples were sectioned at 2 mm to apex (the apical of the root), 4 mm, 6 mm to apex (the middle of the root) and 8 mm to apex (the coronal of the root). The filling void areas were observed by stereomicroscope, and the percentages of void areas in each section were calculated by ImageJ 1.52a. (2) Forty-eight roots of extracted adult molars were selected. After instrumentation, they were randomly divided into 2 groups (n = 8): GF2 group and WVC group. Before root canal filling, the sea-lers were mixed with Rhodamine B dye for visualization under confocal laser scanning microscope. All samples were sectioned at 2 mm to apex (the apical of the root), 5 mm to apex (the middle of the root) and 8 mm to apex(the coronal of the root). Then, the percentages of sealer penetration into dentinal tubules in each section were calculated. RESULTS: At the apical of the root, there were no obvious voids in slight, moderate and severe curved canals in the GF2 group and the WVC group. There was no significant difference between the two groups (P > 0.05). At the middle of the root, there was no significant difference in the percentages of void areas between the two filling methods, but at the coronal of the root, there were more voids in the slight curved root canal in the GF2 group than in the WVC group, and the difference was significant (P = 0.009). The percentages of sealer penetration into dentinal tubules of slight, moderate and severe curved root canals in the GF2 group were 36.10%, 55.80%, 65.08%, respectively. And they were all higher than those in the WVC group (15.78%, 20.70%, 15.61%), respectively, the difference between the two groups was significant (P = 0.001). At the middle of the root, the percentages of sealer penetration into dentinal tubules of slight and moderate curved root canals in GF2 group were also significantly higher than those in the WVC group (P = 0.001). At the coronal of the root, there was no significant difference between the two groups (P > 0.05). CONCLUSION: GuttaFlow2 filling technique has the same sealing effect on the root canal at the apical and middle of the root as the warm vertical technique, but has a better sealing effect on the dentin tubules, especially for severe curved root canal.

In silico toxicity and immunological interactions of components of calcium silicate-based and epoxy resin-based endodontic sealers.

OBJECTIVES: The present study aimed to determine in silico toxicity predictions of test compounds from hydraulic calcium silicate-based sealers (HCSBS) and AH Plus and computationally simulate the interaction between these substances and mediators of periapical inflammation via molecular docking. MATERIALS AND METHODS: All chemical information of the test compounds was obtained from the PubChem site. Predictions for bioavailability and toxicity analyses were determined by the Molinspiration Cheminformatics, pkCSM, ProTox-II and OSIRIS Property Explorer platforms. Molecular docking was performed using the Autodock4 AMDock v.1.5.2 program to analyse interactions between proteins (IL-1ß, IL-6, IL-8, IL-10 and TNF-α) and ligands (calcium silicate hydrate, zirconium oxide, bisphenol-A epoxy resin, dibenzylamine, iron oxide and calcium tungstate) to establish the affinity and bonding mode between systems. RESULTS: Bisphenol-A epoxy resin had the lowest maximum dose tolerated in humans and was the test compound with the largest number of toxicological properties (hepatotoxicity, carcinogenicity and irritant). All systems had favourable molecular docking. However, the ligands bisphenol-A epoxy resin and dibenzylamine had the greatest affinity with the cytokines tested. CONCLUSION: In silico predictions and molecular docking pointed the higher toxicity and greater interaction with mediators of periapical inflammation of the main test compounds from AH Plus compared to those from HCSBS. CLINICAL RELEVANCE: This is the first in silico study involving endodontic materials and may serve as the basis for further research that can generate more data, producing knowledge on the interference of each chemical compound in the composition of different root canal sealers.

Enhancing Coronal Adaptation of Root Canal Fillings with a Modified Single-Cone Obturation Technique: Two Case Reports.

The single-cone technique, also known as the hydraulic condensation technique, is widely employed in endodontics. However, the aforementioned method is presented with certain limitations; specifically concerning the coronal seal and the adaptation of the coronal third of a master gutta-percha (GP) with a round cross-section to the coronal dentinal walls of root canals with semi-round or oval cross-sections. Through two case reports, the current article introduces the coronal vertical condensation (CVC) technique; aiming to enhance GP adaptation to canal walls in similar scenarios. In fact, the coronal vertical condensation technique amalgamates the different aspects of warm vertical condensation and single-cone techniques. In CVC, following the placement of the master GP cone, an electrical heat carrier is inserted immediately a few millimeters apical from the canal orifice to remove the coronal portion of the master GP cone. Subsequently, a hand plugger is used to condense GP in the vertical dimension, and the coronal space is backfilled using melted GP. The implementation of CVC technique has demonstrated an improved coronal adaptation of GP with canal walls. The stated technique seems beneficial; especially in the obturation of severely curved canals or root canals with a final preparation shape of variable taper.

Comparative in vitro analysis of the antifungal activity of different calcium silicate-based endodontic sealers

Aim: This study aimed to perform an in vitro comparative analysis of the antifungal activity of different calcium silicate-based endodontic sealers against three fungal species. Methods: The antifungal properties of three calcium silicate-based sealers were tested: Bio-C Sealer, Cambiar a Sealer Plus BC, and MTA-Fillapex. Two commonly used sealers were used as controls: AH Plus and Endomethasone. An agar diffusion test was performed to analyze the antifungal activity of the sealers against Candida albicans, Candida glabrata, Candida tropicalis, and a mixed microbial culture medium. The results were analyzed using ANOVA (p <0.05). Results: Endomethasone exhibited the highest inhibition against all strains examined, maintaining a consistent level of inhibition throughout 7 days. MTA-Fillapex demonstrated the best performance among the calcium silicate-based sealers for the three fungal species (p < 0.05), maintaining stable values over the 7 days, surpassing that of Endomethasone. Nevertheless, MTA-Fillapex only exhibited antimicrobial effect against the mixed culture for the first 24 hours, and no antimicrobial activity was observed at 48 hours, being surpassed by all tested sealers (p < 0.05). Conclusion: Of all silicate-based sealers tested, only MTA-Fillapex exhibited promising antifungal activity. Nevertheless, care must be taken when extrapolating these results, as MTA-Fillapex exhibited poor antimicrobial activity when tested in mixed microbial cultures

Continuous Wave of Condensation Improves the Filling of Curved Canals: a Micro-CT Study / La condensación de onda contínua mejora el selle de canales curvos: un estudio de micro-CT

Abstract The aim of this study was to compare the filling capacity in curved root canal using a new continuous wave of condensation technique (Termo Pack II, Easy Dental Equipments, Brazil) or lateral compaction. The percentage of voids in the filling of mesial root canals of mandibular molars was assessed by micro-computed tomography (micro-CT). Mesial root canals (n=24) of mandibular molars with a degree of curvature between 20° and 40° were prepared using rotary system (ProDesign Logic, Easy, Brazil) up to #35, .05 taper. The root canals were filled by using the continuous wave of condensation system or lateral compaction and AH Plus sealer (n=12). Scanning at 9 µm was performed after preparation and after filling by using micro-CT SkyScan 1176. The volumetric percentage of filling material and voids (total length and in each root canal third) were calculated. Data were analyzed using ANOVA/ Tukey and Student's t tests (α=0.05). Before the filling techniques, the root canals volume after preparation was similar (p>0.05). The root canals filled by the continuous wave of condensation technique presented the lowest percentage of voids, and the greatest percentage of filling material in total length and thirds (cervical, middle and apical) (p<0.05). Both techniques were not able of completely filling the root canals. The continuous wave of condensation technique Termo Pack II promoted better root canal filling in curved root canals, when compared with lateral compaction.

Resumen El objetivo de este estudio fue comparar la capacidad de obturación en conductos radiculares curvos utilizando una nueva técnica de condensación de onda continua (Termo Pack II, Easy Dental Equipments, Brasil) vs compactación lateral. El porcentaje de brechas en la obturación de los conductos radiculares mesiales de los molares mandibulares se evaluó mediante microtomografía computarizada (micro-CT). Se prepararon conductos radiculares mesiales (n=24) de molares mandibulares con un grado de curvatura entre 20° y 40° utilizando un sistema rotatorio (ProDesign Logic, Easy, Brasil) al #35, conicidad 0,05. Los conductos radiculares se obturaron utilizando un sistema de condensación de onda contínua o compactación lateral y cemento AH Plus (n=12). Se realizó un escaneo de 9 µm después de la preparación y después de la obturación usando el micro-CT SkyScan 1176. Se calculó el porcentaje volumétrico de material de obturación y vacíos (longitud total y en cada tercio del conducto radicular). Los datos se analizaron utilizando las pruebas ANOVA/Tukey y t de Student (α=0,05). Antes de las técnicas de obturación, el volumen de los conductos radiculares después de la preparación fue similar (p>0,05). Los conductos radiculares obturados con la técnica de condensación por onda contínua presentaron el menor porcentaje de vacíos y el mayor porcentaje de material de obturación en longitud total y en tercios (cervical, medio y apical) (p<0,05). Ambas técnicas no fueron capaces de llenar completamente los conductos radiculares. La técnica de condensación de onda contínua Termo Pack II promovió un mejor relleno del conducto radicular en conductos radiculares curvos en comparación con la compactación lateral.

Evaluation of Cytotoxicity, Cell Attachment, and Elemental Characterization of Three Calcium Silicate-Based Sealers.

We investigated three calcium silicate-based sealers with respect to their chemical characterization, cytotoxicity, and attachment to RAW264.7 cells. BioRoot RCS (BR), Bio-C Sealer (BC), and Sealer Plus BC (SPBC) were assessed using Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence spectroscopy (XRF), and energy-dispersive X-ray spectroscopy (EDX) (n = 4) for elemental characterization, and using scanning electron microscopy (SEM) to evaluate cell morphology and adhesion. Cytotoxicity was determined at different dilutions (1:1, 1:2, and 1:5) using the succinate dehydrogenase activity (MTT assay). Statistical analysis was performed for normal distribution using the Shapiro-Wilk test and for homoscedasticity using Levene's test, and one-way ANOVA, Tukey's/Dunnett's post hoc tests for cell viability and XRF (α = 0.05). Calcium silicate hydrate and calcium hydroxide were detected by FTIR in all groups. EDX detected a higher calcium content for BR and SPBC and aluminum only in the premixed sealers. XRF detected the highest calcium release in BR (p < 0.05). The surface morphology showed irregular precipitates for all the sealers. SPBC at a 1:2 dilution resulted in the lowest cell viability compared to BR (p < 0.05) and BC (p < 0.05). The calcium silicate-based sealers produced a statistically significant reduction in cellular viability at a 1:1 dilution compared to the control group (p < 0.0001). All the sealers maintained viability above 70%.

Biocompatibility of three different root canal sealers, experimental study.

OBJECTIVES: This study was assessed the biocompatibility of three different root canal sealers (Well-Root St, GuttaFlow Bioseal, and AH-Plus) following implantation in rat subcutaneous tissues, using histopathological immunohistochemical analysis. METHODS: Four groups of eighty-four male rats each underwent subcutaneous dorsal implantation of a polyethylene tube, either empty or filled. Tissues were collected, fixed, and processed for histological analysis after 7, 15, and 30 d. Slides were photographed and digitally processed to identify lymphocytes and macrophages using Cluster of differentiation 3 (CD3) and cluster of differentiation 68 (CD68) markers, respectively. P was set at 0.05, when lymphocyte and macrophage infiltration was compared between groups and observation times using one-way analysis of variance (ANOVA). RESULTS: Histopathological analysis of all groups revealed an inflammatory reaction followed by the emergence of a fibrous capsule after 7 days. After 30 days, the thickness of the fibrous capsule and the inflammatory response subsided. CD3 staining for immunohistochemical analysis revealed that the AH-Plus group had the highest mean percentage of lymphocyte infiltration at 7 and 15 days, followed by the Well-Root St, GuttaFlow Bioseal, and Control groups. After 30 days, no discernible difference was observed between the groups in terms of the mean percentage of lymphocyte infiltration. After 7, 15, and 30 days, there was a significant difference in the mean percentage of macrophage infiltration across the groups, as demonstrated by CD68 staining. After 7, 15, and 30 days, the AH-Plus group had the highest mean percentage of macrophage infiltration, followed by the Well-Root St. and GuttaFlow Bioseal groups, while the control group had the lowest mean percentage. CONCLUSION: All observational periods showed minimal inflammatory reactions to GuttaFlow Bioseal. After subcutaneous tissue implantation in a rat model, the initial inflammatory reactions to Well-Root St and AH-Plus had abated by day 30, and all tested sealers had outstanding biocompatibility.

Effect of blood contamination on marginal adaptation of cold ceramic and MTA angelus: a scanning electron microscopic study.

BACKGROUND: This study aimed to assess the effect of blood contamination on marginal adaptation of cold ceramic (CC) and mineral trioxide aggregate (MTA) Angelus using scanning electron microscopy (SEM). METHODS: This in vitro experimental study was conducted on 24 extracted single-rooted human teeth. After cleaning and shaping, the root canals were filled with lateral compaction technique. The apical 3 mm of the roots was cut, and cavities with 3 mm depth were created at the apex. The teeth were randomly assigned to two group (n = 12) for the application of CC and MTA Angelus as retrograde filling materials. CC and MTA Angelus were prepared by mixing the powder with blood, and applied in the cavities. After 24 h, their marginal adaptation to the canal walls was assessed by SEM. Data were statistically analyzed by t-test (alpha = 0.05). RESULTS: The mean marginal gap was 8.98 µm in the CC, and 16.26 µm in the MTA Angelus group; this difference was statistically significant (P < 0.001). CONCLUSIONS: The present in vitro study revealed that following complete blood contamination of powder, CC showed significantly superior marginal adaptation than MTA Angelus as shown by SEM assessment.

Assessment of the root filling volume in C-shaped root canal on cone-beam CT and micro-CT in relation to nano-CT.

AIM: To assess the observed volume of filled C-shaped root canals from different CBCT and micro-CT having nano-CT as a reference. MATERIALS AND METHODS: Twelve extracted mandibular molars with C-shaped root canals were endodontically treated using Reciproc Blue R25 (VDW GMBH, Munich, Germany) in a reciprocating system and filled with gutta-percha (Dentsply Maillefer) and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany). CBCT scans were performed using 3 units-3D Accuitomo 170 (J. Morita, Kyoto, Japan), ProMax 3D Max (Planmeca, Helsinki, Finland), and NewTom VGi EVO (Cefla QR, Verona, Italy)-at two resolution modes: standard and high. Micro-CT and nano-CT scans were also obtained. The volume of all filled C-shaped root canals was obtained using CTAn software (Bruker, Kontich, Belgium), and the blooming artifact, in relation to nano-CT volume, was calculated. The data were evaluated by the Bland-Altman plots and ANOVA two-way for repeated measures (α = 0.05). RESULTS: All CBCT units and micro-CT showed significantly larger observed volume of root canal filling when compared to nano-CT. The blooming artifact of root canal filling in standard resolution was significantly larger than that in high resolution (p < 0.05) in all CBCT units. CONCLUSIONS: Endodontic filling material with AH Plus sealer causes blooming artifacts in CBCT units and micro-CT. CLINICAL RELEVANCE: Considering the anatomical complexity of C-shaped root canals and the challenges associated with endodontic treatment, CBCT is frequently recommended for follow-up evaluations. However, the presence of endodontic filling material can result in blooming artifacts that may potentially impact the accurate diagnosis of endodontic complications.

Root filling quality and bond strength of endodontic sealers to human and bovine dentin / Qualidade da obturação e resistência de união de cimentos endodônticos à dentina humana e bovina

Objetivo: Este estudo teve como objetivo comparar a qualidade da obturação e a resistência de união de dois cimentos endodônticos, AH Plus e Bio-C Sealer, em dentes humanos e bovinos. Métodos: Os canais radiculares de 60 dentes unirradiculares [30 humanos (H) e 30 bovinos (B)] foram preparados e obturados por condensação lateral da guta-percha e AH Plus (grupos AP-H e AP-B) ou Bio-C Sealer (grupos BC-H e BC-B). Seis fatias de 1,5 mm de espessura foram obtidas de cada raiz. Os espécimes foram observados em estereomicroscópio para avaliar a qualidade da obturação, considerando possíveis espaços vazios no material obturador. Posteriormente, as fatias radiculares foram avaliadas em termos de resistência de união por push-out e modo de falha. Os dados foram analisados pelos testes de Mann-Whitney e coeficientes de correlação de Spearman (α=5%). Resultados: A qualidade de obturação fornecida por AP e BC foi semelhante em ambos os substratos de dentina. No entanto, ao comparar dentes humanos e bovinos, os escores de espaços vazios foram maiores nas amostras bovinas, para ambos os cimentos. AP teve maior resistência de união à dentina humana e bovina do que BC. No entanto, não houve diferença significativa na resistência de união entre os substratos dentinários, para ambos os cimentos testados. Além disso, houve uma correlação positiva e moderada entre os valores de resistência de união de dentes humanos e bovinos. O modo de falha misto foi o mais prevalente. Conclusão: AP e BC fornecem qualidade de obturação semelhante, mas o primeiro apresenta maiores valores de resistência de união à dentina humana e bovina. A utilização de dentes bovinos como substitutos de amostras humanas parece ser adequada em estudos relacionados à resistência de união, mas não naqueles que testam a qualidade da obturação endodôntica.(AU)

Objective: This study aimed to compare the filling quality and bond strength of two endodontic sealers, AH Plus and Bio-C Sealer, in human and bovine teeth. Methods: The root canals of 60 [30 human (H) and 30 bovine (B)] single-rooted teeth were prepared and filled by lateral condensation of gutta-percha and AH Plus (groups AP-H and AP-B) or Bio-C Sealer (groups BC-H and BC-B). Six 1.5-mm-thick slices were obtained from each root. The specimens were observed under a stereomicroscope to assess filling quality, considering possible voids within the filling material. Subsequently, root slices were evaluated in terms of push-out bond strength and failure mode. Data were analyzed by Mann-Whitney tests and Spearman correlation coefficients (α=5%). Results: The filling quality provided by AP and BC was similar in both dentin substrates. However, when comparing human and bovine teeth, void scores were greater in the bovine samples, for both sealers. AP had higher bond strength to human and bovine dentin than BC. However, there was no significant difference in bond strength between dentin substrates, for both sealers tested. Also, there was a positive and moderate correlation between the bond strength values of human and bovine teeth. The mixed failure mode was the most prevalent. Conclusion: AP and BC provide similar filling quality, but the first presents higher bond strength values to human and bovine dentin. The use of bovine teeth as substitutes for human samples seems adequate in studies related to bond strength, but not in those testing root canal filling quality.(AU)

Biocompatibility of Ajwain Oil Combined with Eugenol and Zinc Oxide as a Deciduous Root Canal Obturating Material: An In Vivo Study.

Aim and objectives: The present study was intended to assess the biocompatibility of newly formulated materials such as zinc oxide (ZO) admixed with ajwain oil (A) as well as ajwain eugenol (E) (1:1 ratio) against ZOE through an animal model as root canal obturating materials in deciduous teeth. Materials and methods: The study involved randomly selected 24 albino rats, which were divided into three groups based on test materials. Two polyethylene tubes (PETT) (8 mm long × 1 mm internal diameter) were inserted into connective tissues of the dorsal side on either side of each rat viz empty tube (negative control) and another containing test material (test group). Animals were sacrificed at the end of the 7th and 21st days. PETT with surrounding connective tissues were excised. Histopathological evaluations of the material's biocompatibility were done by determining inflammatory tissue responses. Non-parametric tests such as Kruskal-Wallis and Mann-Whitney U were used for statistical analysis (p < 0.05). Results: Histopathological examination on the 7th day showed increased polymorphonuclear cells for all test materials compared to the negative control (p = 0.92), suggesting acute inflammation. The inflammation subsided gradually after 21 days (p = 0.48). The lymphocytes increased after 21 days for all the materials indicating chronic inflammation (p = 0.79), as well as fibroblasts (p = 0.34) and capillaries (p = 0.35), indicating healing and repair. Conclusion: The newly formulated obturating materials were found to be biocompatible compared to ZOE. How to cite this article: Dahake PT, Joshi SS, Kale YJ, et al. Biocompatibility of Ajwain Oil Combined with Eugenol and Zinc Oxide as a Deciduous Root Canal Obturating Material: An In Vivo Study. Int J Clin Pediatr Dent 2023;16(3):431-436.

Different Dentin Conditioning Protocols on Bond Strength of a Bioceramic Root Canal Filling.

Objective: Bioceramic-based sealers, in combination with bioceramic-coated gutta-perchas, have become more commonly used in root canal obturation. The present study aimed to assess the influence of laser-assisted dentin conditioning compared with conventional conditioning protocols on the push-out bond strength (PBS) of a bioceramic-based root canal filling. Material and Methods: Sixty extracted mandibular premolars with one root canal were instrumented with EndoSequence rotary files up to size 40/0.04. Four types of dentin conditioning protocols were used: 1) 5.25% NaOCl (control), 2) 17% EDTA+5.25% NaOCl, 3) Diode laser-agitated 17% EDTA+5.25% NaOCl, 4) Er,Cr:YSGG laser irradiation+5.25% NaOCl. Teeth were obturated using the single-cone technique with EndoSequence BC sealer+BC points (EBCF). After having obtained 1-mm-thick horizontal slices from the apical, middle and coronal root thirds, push-out test was carried out, and failure modes were determined. The data were analyzed by two-way analysis of variance and Tukey's test with a significance level of p<0.05. Results: The apical segments showed the highest PBS in all groups (p<0.05). In the apical segments, EDTA+NaOCl and diode laser agitated EDTA increased the PBS compared to the control (p=0.0001) and Er, Cr: YSGG laser (p=0.011 and p=0.027, respectively) groups. Both laser-used groups revealed significantly higher PBS values in the middle and coronal segments than EDTA+NaOCl (p<0.05). The bond failure was predominantly cohesive without any significant difference among the groups (p>0.05). Conclusions: Laser-assisted dentin conditioning had distinct effects on the PBS of the EBCF at different root segments. Although Er, Cr: YSGG was ineffective in the apical segments, generally, laser-assisted dentin conditioning affected PBS more favorably than conventional irrigation groups, with a more pronounced effect in the diode laser-agitated EDTA group.

Influence of a Metal Artifact Reduction Filter on the Diagnostic Accuracy of Complete and Incomplete Vertical Root Fractures.

INTRODUCTION: This study aimed to assess the influence of the e-vol DX BAR filter on the diagnostic accuracy of complete and incomplete vertical root fractures (VRFs). METHODS: Twenty single-rooted teeth were selected. The tooth crowns were removed, and the root canals were prepared up to a 40/.06 instrument (ProTaper Next). Each specimen was scanned in a Prexion 3D cone-beam computed tomography (CBCT) device, in a dry human skull, in 4 different situations: no root canal filling, gutta-percha, fiberglass post, and metal post. The specimens were fractured in a universal testing machine by using a customized wedge. Each specimen was reinspected to confirm the presence of incomplete VRFs. Another set of CBCT scans was performed. Then, the fractures were completed in the universal testing machine, the teeth were reinspected, and the CBCT images were acquired again. Images were assessed by using the e-Vol DX software system, with the BAR filter and with the original images, for the diagnosis of VRFs. Statistical analysis was performed by using the DeLong and McNemar tests for the comparison of the area under the receiver operating characteristic curves (AUC), accuracy, sensitivity, and specificity values. RESULTS: The use of the BAR filter did not improve the diagnostic values of AUC, accuracy, sensitivity, and specificity in both fracture patterns (P > .05). Incomplete VRFs presented significantly lower AUC, accuracy, and sensitivity compared with complete VRFs (P < .0001). CONCLUSIONS: The BAR filter did not improve the diagnostic accuracy of VRFs. The intracanal materials also did not influence the diagnosis. Incomplete VRFs were highly associated with a decrease in sensitivity.

Histological evaluation of ProRoot mineral trioxide aggregate and Cold ceramic as root-end filling materials in animal models.

Background: This study aimed to evaluate the reaction of the periapical tissue to Cold ceramic and mineral trioxide aggregate (MTA) following periapical endodontic surgery. Materials and Methods: In this experimental study, a total of 12 mandibular first, second, and third premolars of two male dogs were selected. All procedures were performed under general anesthesia. The access cavities were prepared, and the length of canals was determined. Root canal treatment was performed. A week later, periradicular surgery was performed. After osteotomy, 3 mm of the root end was cut. Then, a 3-mm cavity was created by an ultrasonic. The teeth were randomly divided into two groups (n = 12). The root-end cavities were filled with MTA in the first group and with Cold ceramic in the second group. After 4 months, the animals were scarified. Histological evaluation of the periapical tissues was performed. Data were analyzed using SPSS 22 and Chi-square test and P = 0.05. Results: The findings showed 87.5% and 58.3% cementum formation in MTA and Cold ceramic groups, respectively, indicating a significant difference (P < 0.001). In addition, the results showed 91.7% and 83.3% bone formation in MTA and Cold ceramic groups, respectively, but the difference was not statistically significant (P = 0.6). Furthermore, the findings revealed 87.5% and 58.3% periodontal ligament (PDL) formation in MTA and Cold ceramic groups, respectively (P = 0.05). Conclusion: Cold ceramic was able to induce the regeneration of cementum, bone, and PDL; hence, it can be considered as a biocompatible root-end filling material in endodontic surgery.

Antibacterial activity and physicochemical properties of a sealer containing copaiba oil.

This study aimed to evaluate the antimicrobial activity and physicochemical properties of a novel dual-cure endodontic sealer containing copaiba oil. The copaiba oil was obtained and characterized by gas chromatography (GC), and the minimum inhibitory concentration (MIC) was performed. The experimental sealers were formulated with copaiba oil concentrations of 0, 0.5, 1, and 2%, and the RealSeal™ (Sybron endo, Orange, USA) and AH Plus (Dentsply De Trey Gmbh, Konstanz, Germany) were used as the commercial references. The antimicrobial activity of the sealers was evaluated by the direct contact test for 1h and 24h. To evaluate the physicochemical properties of the sealers, the degree of conversion, setting time, film thickness, dimensional stability, and radiopacity tests were performed. The data were statistically analyzed by one-way ANOVA and Tukey's test (α = 0.05). Concerning the results, the sealers containing copaiba oil showed antimicrobial activity without harming the physicochemical properties.

Synthesis and characterization of calcium-releasing elastomeric resin-based endodontic sealers.

OBJECTIVES: To evaluate the incorporation of halloysite nanotubes (HNTs) loaded with one of two calcium sources (i.e., calcium hydroxide/CaOH2 or beta-tricalcium phosphate/ß-TCP) on the physicochemical and biological properties of an experimental resin-based dual-cured endodontic sealer. MATERIALS AND METHODS: HNTs were encapsulated with CaOH2 or ß-TCP at 10 wt.%. HNTs containing CaOH2 or ß-TCP were added into the experimental sealers at 50 wt.%. The control sealers were the calcium-free HNT-modified resin-based experimental sealer and AH Plus™, a commercially available endodontic sealer. Degree of conversion, setting time, flow, film thickness, radiopacity, dimensional stability, and calcium ions release were determined. Antibiofilm properties and cytocompatibility of the formulated sealers and commercial control were also evaluated. One and two-way ANOVA analysis followed by Tukey's post hoc test was conducted to evaluate the effect of the independent variable on the evaluated properties. RESULTS: FTIR confirmed the encapsulation of calcium sources into HNTs. Regarding flow and film thickness, the values obtained from these sealers were in accordance with the specifications provided by ISO 6876. For radiopacity, AH Plus™ achieved the highest radiopacity (p<0.05). Among the experimental formulations, all experimental HNT-containing compositions exhibited values below 3 mm Al. The experimental sealers showed greater dimensional changes when compared to the commercial (AH Plus™) control. The release of calcium ions was observed for the HNT_CaOH2 and HNT_ß-TCP sealers without statistical differences. Experimental sealers containing HNT_CaOH2 and HNT_ß-TCP significantly reduced the CFU/mL count and showed cell compatibility. CONCLUSIONS: The findings of this study demonstrate that the incorporation of HNT_CaOH2 or HNT_ß-TCP into resin-based experimental sealers promoted antimicrobial effects and gradual calcium release without impairing cytocompatibility or physicochemical properties of the sealers. Still, an adjustment to reach the minimal radiopacity established by ISO 6876 is needed. CLINICAL RELEVANCE: The experimental resin-based sealers seemed to be an alternative for endodontics. The incorporation of calcium sources exerts promising antimicrobial effects while displaying low cell toxicity.